比一比,看谁算得又对又快.475÷19= 725÷29=800÷50= 1000÷40=500÷20= 750÷30=400÷25= 500÷20=
直接写数对又快:+= ﹣= 2012×=56÷11×165÷7= ×[0.75+(﹣)]= 40÷[×(+)]=
口算.80×20%= 24×0.2= 5﹣= ÷3= 32=36÷12%= 1﹣0.3= 2.1+3.25= ×1.8= (0.2)2×52=
直接写出得数.2.8÷0.125= 4.38﹣3.42+5.62﹣2.08= == 9.08×9+9.08= =
直接写出得数.④36.36÷36=②×=③2.5×1.5×4=
直接写得数.1÷0.05= 0.325+= (0.2)2=10﹣0.01= = 3.1×0.7=